Naresh Trehan

A comparative evaluation of intrapleural and thoracic epidural analgesia for postoperative pain relief after minimally invasive direct coronary artery bypass surgery

OBJECTIVEnTo compare the efficacy of thoracic epidural analgesia (TEA) and intrapleural analgesia (IPA) after minimally invasive direct coronary artery bypass (MIDCAB) surgery with regard to quality of analgesia and complications.nnnDESIGNnA prospective, randomized study.nnnSETTINGnA specialty research hospital.nnnPARTICIPANTSnFifty consenting adults scheduled for MIDCAB surgery.nnnINTERVENTIONSnAll patients underwent elective MIDCAB surgery. Patients in the TEA group (n=25) had an epidural catheter inserted in the fourth to fifth thoracic interspace and those in the IPA group (n=25) had an intrapleural catheter inserted in the sixth to seventh intercostal space intraoperatively under vision.nnnMEASUREMENTS AND MAIN RESULTSnParameters evaluated after administration of bupivacaine (8 mL of 0.25% in the TEA group and 20 mL of 0.25% in the IPA group) on first demand included visual analog scale (VAS) pain scores, cardiovascular and respiratory (clinical, blood gases) function, wakefulness, supplemental analgesic requirement, and complications. Measurements were made at 2-hour intervals for the next 12 hours. VAS scores were significantly lower at 2, 6, 8, and 12 hours in the IPA group (TEA = 3.5, 4.5, 4.9, 4.6; IPA = 2.2, 3.6, 3.5, 3.7). There were no significant differences in hemodynamic or respiratory parameters or postoperative requirement for supplemental analgesia. In the TEA group, three patients had catheter migration and four had severe backache.nnnCONCLUSIONnIPA is a safe and effective technique for postoperative analgesia after MIDCAB surgery and has a low complication rate compared with TEA. Careful positioning, chest tube clamping, and anchoring of the catheter are mandatory for IPA to be effective.

Evaluation of Right Ventricular Function During CABG: Transesophageal Echocardiographic Assessment of Hepatic Venous Flow Versus Conventional Right Ventricular Performance Indices.

The vulnerability of right ventricle (RV) to ischemic insult during cardiac surgery is being increasingly recognized. This study aims to evaluate right ventricular function by measuring hepatic venous flow (HVF) patterns using intraoperative transesophageal echocardiography (TEE), and to compare HVF with other conventional two‐dimensional echocardiographic and hemodynamic indices of RV performance. Patients undergoing coronary artery bypass grafting (CABG) were studied intraoperatively using a multiplane dual frequency 5/3.7‐MHz phased array transducer, a pulmonary artery catheter, and an arterial catheter. Peak velocities and time velocity integrals of HVF pattern were studied. Peak systolic‐diastolic ratio (S/D) of biphasic HVF and reverse flow ratio (% reverse flow/forward flow =% RF/FF) were also examined. Two‐dimensional echocardiographic measurements included: (1) transverse plane long‐axis (LA) and short‐axis (SA) planimetered areas expressed as ratios; LA maximum major and minor‐axis shortening fractions; (2) tricuspid annular plane systolic excursion (TAPSE) ratio. All data were obtained after induction of anesthesia (stage 1), after sternotomy (stage 2), aftercardiopulmonary bypass (CPB) (stage 3), and after sternal closure (stage 4). Pre‐CPB all 35 patients had biphasic HVF by Doppler. In 31 patients peak S/D ratio was > 1. After CPB, there was significant reduction in systolic forward flow (S wave), along with an increase in late systolic reverse flow (V wave) and an increase in % RF/FF. At this stage TAPSE ratio decreased (pre CPB 0.33 ± 0.12 vs post CPB 0.30 ± 0.11). There was simultaneous decrease in 2‐D long‐axis LA (pre CPB 0.52 ± 0.11 vs post CPB 0.31 ± 0.01) and max major axis LA (pre CPB 0.38 ± 0.06 vs post CPB 0.31 ± 0.11). Max major axis LA correlated significantly with changes in right atrial pressure (P < 0.05). Tricuspid annular motion diminished significantly at sternal closure. Hepatic systolic forward flow and TAPSE ratio can be an indirect measure of RV systolic functions in correlation with maximum major axis LA changes. Evaluation of HVF provides unique insight into right ventricular dynamics. It is an easy, safe, and sensitive method for assessing RV functions intraoperatively.

Thoracic epidural analgesia in obese patients with body mass index of more than 30 kg/m 2 for off pump coronary artery bypass surgery

Perioperative Thoracic epidural analgesia (TEA) is an important part of a multimodal approach to improve analgesia and patient outcome after cardiac and thoracic surgery. This is particularly important for obese patients undergoing off pump coronary artery bypass surgery (OPCAB). We conducted a randomized clinical trial at tertiary care cardiac institute to compare the effect of TEA and conventional opioid based analgesia on perioperative lung functions and pain scores in obese patients undergoing OPCAB. Sixty obese patients with body mass index >30 kg/m2 for elective OPCAB were randomized into two groups (n=30 each). Patients in both the groups received general anesthesia but in group 1, TEA was also administered. We performed spirometry as preoperative assessment and at six hours, 24 hours, second, third, fourth and fifth day after extubation, along with arterial blood gases analysis. Visual analogue scale at rest and on coughing was recorded to assess the degree of analgesia. The other parameters observed were: time to endotracheal extubation, oxygen withdrawal time and intensive care unit length of stay. On statistical analysis there was a significant difference in Vital Capacity at six hours, 24 hours, second and third day postextubation. Forced vital capacity and forced expiratory volume in one second followed the same pattern for first four postoperative days and peak expiratory flow rate remained statistically high till second postoperative day. ABG values and PaO2/FiO2 ratio were statistically higher in the study group up to five days. Visual analogue scale at rest and on coughing was significantly lower till fourth and third postoperative day respectively. Tracheal extubation time, oxygen withdrawal time and ICU stay were significantly less in group 1. The use of TEA resulted in better analgesia, early tracheal extubation and shorter ICU stay and should be considered for obese patients undergoing OPCAB.

Predictors of Early Outcome After Coronary Artery Surgery in Patients with Severe Left Ventricular Dysfunction

Abstract Background: The surgical survival in patients with severe myocardial dysfunction is critically dependent on the selection of patients. The present study was undertaken to identify the prognostic factors in such patients. Methods: We analyzed the data of 176 consecutive patients (161 men, 15 women), aged 29 to 88 years (mean 58.43), with a left ventricular ejection fraction (LVEF) <30% who underwent isolated coronary artery bypass grafting. The LVEF ranged from 15% to 30% (mean 27.18%). Preoperatively, 33% had angina, 19.9% had recent myocardial infarction, and 21.6% had congestive heart failure. The mean number of grafts was 2.5/patient. The intra‐aortic balloon was used prophylactically in 20.5% of patients and therapeutically in 4.0% of patients. Results: The hospital mortality was 2.3%. The complications occurred as follows: perioperative myocardial infarction in two (1.1%), intractable ventricular arrhythmias in two (1.1%), prolonged ventilation in four (2.3%) and peritoneal dialysis in 1 (0.6%). The mean ICU and hospital stay were2.46 ± 0.76and7.57 ± 2.24days, respectively. The predictors of survival on univariate analysis were New York Heart Association (NYHA) class(x2 = 14.458, p < 0.001), recent myocardial infarction(x2 = 5.852, p = 0.016), congestive heart failure (CHF)(x2 = 5.526, p = 0.019), and left ventricular end‐systolic volume index (LVESVI)(x2 = 25.833, p < 0.001). However, on multivariate analysis, left ventricular end‐systolic volume index was the only independent left ventricular function measurement predictive of survival(x2 = 10.228, p = 0.001). Conclusion: Left ventricular end‐systolic volume index is the most important predictor of survival after coronary artery bypass surgery in patients with severe myocardial dysfunction.(J Card Surg 2003;18:101‐106)

Ascending Aortic Aneurysm Resection: 15 Years’ Experience:

Between September 1989 and June 2004, 148 consecutive patients underwent ascending aortic replacement for aneurysm or dissection. There were 130 males (88%) and 18 females (12%). Their mean age was 46.20 ± 13.36 years. Fifty-seven patients (39%) were treated for type 1 and type 2 aortic dissection, and 91 (61%) for ascending aortic aneurysm. The Bentall procedure was performed in 81 patients (55%), the Cabrol procedure in 7 (5%), separate ascending aortic replacement and aortic valve replacement or repair was carried out in 24 (16%), and ascending aortic replacement only in 36 (24%). Hospital mortality was 4.05% (6 deaths). On univariate analysis, left ventricular ejection fraction ≤ 30%, emergency surgery, contained rupture, concomitant coronary artery bypass grafting, and age ≥ 65 years were risk factors for early mortality. However, on multivariate analysis, ejection fraction ≤ 30% and contained rupture were the only factors significantly associated with early mortality. The long-term survival rates were 87.2% ± 3.7% at 5 years, 78.0% ± 5.6% at 10 years, and 60.9% ± 9.9% at 15 years. Ascending aortic resection for aneurysm or dissection can be performed with low mortality and morbidity.

Multimodality Targeted Approach in Redo Off-Pump Coronary Artery Bypass Surgery

Records of 86 patients who underwent off-pump redo coronary revascularization between December 1997 and December 2000, were analyzed. Approaches included median sternotomy (47), anterolateral thoracotomy for left anterior descending artery and diagonal targets (35), posterolateral thoracotomy for the obtuse marginal with proximal anastomosis on descending aorta (3), and a combined subxiphoid-anterior thoracotomy approach (1) for right gastroepiploic artery-to-left anterior descending artery anastomosis. The mean age was 61.82 years. There were 2 (2.3%) operative deaths. Complications included perioperative myocardial infarction in 4 patients and reexploration for bleeding in one. Blood transfusion was required in 12 patients. The mean length of hospital stay was 5 ± 2 days. A multimodality targeted approach for off-pump redo coronary artery bypass offers a less invasive but safer method of myocardial revascularization, with decreased complications, lower blood product requirement, and early hospital discharge.

Anesthetic management of right atrial mass removal and pulmonary artery thrombectomy in a patient with primary antiphospholipid antibody syndrome.

Antiphospholipid antibody syndrome (APLAS) characterises a clinical condition of arterial and venous thrombosis associated with phospholipids directed antibodies. APLAS occurs in 2% of the general population. However, one study demonstrated that 7.1% of hospitalised patients were tested positive for at least one of the three anticardiolipin antibody idiotype. Antiphospholipid antibodies often inhibit phospholipids dependent coagulation in vitro and interfere with laboratory testing of hemostasis. Therefore, the management of anticoagulation during cardiopulmonary bypass can be quite challenging in these patients. Here, we present a case of right atrial mass removal and pulmonary thrombectomy in a patient of APLAS.

What Is the Double Shadow in the Chest

F N 62-YEAR-OLD diabetic patient underwent coronary artery bypass graft surgery. A pulmonary artery catheter PAC) and a triple-lumen catheter (TLC) were inserted through he right internal jugular vein (RIJV) without any difficulty at he time of anesthesia. On the third postoperative day, the chest adiograph revealed a double shadow at the distal end of the AC (Fig 1). The radiologist’s report on that x-rays was “steral sutures seen in situ, two Swan-Ganz catheters seen in situ, eft pleural effusion, right costophrenic (CP) angle is clear. Rest f the visualized lung fields are clear.” Earlier postoperative hest x-rays did not show any abnormality in the PAC and LC. Physical examination of the patient showed the PAC with